1. Field of the Invention
The present invention relates to a digital recorder which is capable of recording, reproducing and editing an audio signal in a digital fashion.
2. Description of the Related Art
As a method of recording, reproducing and editing an audio signal, a technique has been conventionally employed which records the audio signal on a magnetic tape, and reproduces the audio signal from the magnetic tape and edits it. Since such a prior art involves an analog recording and reproducing process, deterioration in sound quality of the reproduced signal is inevitable. Prominent deterioration in the sound quality will appear particularly when the once-recorded audio signal is dubbed.
Further, use of the magnetic tape as a recording medium raises problems such that it takes time to reach a target editing point on the magnetic tape, and edition requires that the target recorded portion be physically cut and pasted or copied to somewhere else before actually executing the editing operation.
The problem about the deterioration in sound quality can be overcome by employing a method of digital recording a signal on a magnetic tape. There still remains, however, a shortcoming concerning the freedom of locating the starting point or edition due to use of a sequential-access type recording medium.
There have been proposed solutions to the conventional problems, solutions which use a hard disk and a magneto-optical disk as a memory medium. For instance, refer to U.S. Ser. No. 07/690,710 filed on Apr. 24, 1991 Inventor: Nobuo IIZUKA (abandoned in favor of CIP application Ser. No. 07/871,241 filed on Apr. 20, 1992); U.S. Ser. No. 07/752,876 filed on Aug. 30, 1991 Inventor: Atushi MIYAKE; U.S. Ser. No. 07/795,983 filed on Nov. 22, 1991 Inventor: Nobuo IIZUKA (abandoned in favor of continuation application Ser. No. 08/132,445 filed on Oct. 6, 1993); and U.S. Ser. No. 07/807,053 filed on Dec. 12, 1991 (abandoned in favor of continuation application Ser. No. 08/164,305 filed on Dec. 8, 1993).
In recording and reproducing a sound on or from an external memory medium such as a hard disk and a magneto-optical disk, a so called punch-in and punch-out process is to be executed to replace with another audio signal a specific content of an audio signal which was recorded in a specific area on a certain track.
Since the punch-in and punch-out process needs time for accessing the external memory medium, consideration has to be paid to delay in timing of punch-in and punch-out. The punch-in and punch-out process must be also executed with care not to generate a vain time of missing sound.